Use of treating elements to facilitate flow in vessels

ABSTRACT

A method for facilitating the distribution of the flow of one or more streams within a bed vessel is provided. Disposed within the bed vessel are internal materials and structures including multiple operating zones. One type of operating zone can be a processing zone composed of one or more beds of solid processing material. Another type of operating zone can be a treating zone. Treating zones can facilitate the distribution of the one or more streams fed to processing zones. The distribution can facilitate contact between the feed streams and the processing materials contained in the processing zones.

RELATED APPLICATIONS

This application is a continuation application and claims the benefit,and priority benefit, of U.S. patent application Ser. No. 16/379,266,filed Apr. 9, 2019, which is application is a continuation applicationand claims the benefit, and priority benefit, of U.S. patent applicationSer. No. 16/105,781, filed Aug. 20, 2018, which is a continuation andclaims the benefit, and priority benefit, of U.S. patent applicationSer. No. 15/720,751, filed Sep. 29, 2017, which is a continuation andclaims the benefit, and priority benefit, of U.S. patent applicationSer. No. 15/676,603, filed Aug. 14, 2017, which claims the benefit andpriority benefit of U.S. patent application Ser. No. 15/265,405, filedSep. 14, 2016, which claims the benefit and priority benefit of U.S.Provisional Patent Application Ser. No. 62/314,069, filed Mar. 28, 2016and, which claims the benefit and priority benefit of U.S. ProvisionalPatent Application Ser. No. 62/294,768, filed Feb. 12, 2016, thecontents of each are incorporated by reference herein in their entirety.

BACKGROUND 1. Field of the Invention

The presently disclosed subject matter relates to facilitating the flowof streams within vessels utilized in the process industry.

2. Description of Related Art

The number of bed vessels installed and operating in industry totals inthe tens of thousands worldwide. Bed vessels are usually large withdiameters ranging from 4 to 18 feet and heights from 10 to over 100feet. The volume of such bed vessels is substantially filled with bedvessel internals. Each year, the number of bed vessels that are shutdownor are constructed and commissioned totals in the hundreds. The designedlifetime of these bed vessels is typically measured in decades. Bedvessels used in industry contain appropriate internals which can includeone or more beds of solid processing material elements which facilitateintended processing operations. Such solid processing material elementscan include, for example, reaction-promoting catalysts and masstransfer-promoting agents including sieves and sorbents. Bed vessels andtheir contents represent a very sizable investment by the bed vesselowner.

The normal length of a typical bed vessel “on oil” operating cycle (fromvessel startup to vessel shutdown) is measured in months or years.Normal operations are usually halted when bed vessel internals reachperformance limits or when bed vessel operating conditions, such astemperature or pressure, exceed operating limits. Such shutdowns aretypically followed by rejuvenation of, repair to and/or replacement ofbed vessel internals followed by restart of operations.

It is known in the art to utilize suitable materials to promote flowdistribution for streams entering bed vessels. The purpose of suchdistribution is to subdivide the streams into rivulets which improvestream contact with bed vessel processing materials. Three dimensionalreticulates are known to promote flow distribution. For example, U.S.Pat. Nos. 6,258,900, 6,291,603 and 7,265,189 each describes suchreticulated materials.

Many bed vessels face challenges associated with sustaining effectiveand efficient utilization of bed vessel internals including effectiveand efficient stream flow distribution across and throughout the beds ofsolid processing material elements installed in the bed vessels.Inadequate stream flow distribution leads to coalescence of small streamrivulets into larger streams resulting in stream flow channeling whichcan result in bypassing portions of the bed vessel processing internals.

Stream flow channeling within a bed vessel can occur and change overtime due to shifts in operating conditions (e.g., changing compositionsof feed streams), operations upsets (e.g., power surges/cuts, pumpfailures, etc.), natural or accelerated aging of bed vessel internalsand the like. Channeling can occur when coalescence is facilitated bysmaller fluid streams contacting each other or by contact with other bedvessel internals or with the bed vessel itself. Channeling isundesirable because it results in areas of underexposed andunderutilized bed vessel internal materials and areas of overexposedmaterials. The former can result in significant loss of bed vesselproductivity and profitability. The latter can result in so-called “hotspots” where sharp temperature gradients cause damage to the vessel andits internals.

One approach to coping with these situations has been to toleratemoderate bed vessel underperformance and operate the vessel untilperformance has degraded to an unacceptable level. At such a time, thebed vessel is shutdown so that bed vessel internals can be adjusted,rejuvenated or replaced. This mode of operation results in reduced“on-oil” operating time with accompanying loss of bed vesselproductivity and profitability.

Another approach has been to install one or more conventional structuredengineering devices at appropriate locations within the bed vessel tofacilitate flow redistribution within and across the cross section ofbed vessels and, in doing so, increase stream flow contact with bedvessel internals (including beds of solid processing materials) andreduce the negative consequences of stream flow channeling. Suchconventional devices include engineered equipment structures that aretypically form-fitted to the inside of the bed vessel and which canoccupy up to ten feet of depth within the bed vessel. Such devices arecostly to design, fabricate, install, operate and maintain and requiresspecially-trained personnel to do so. These conventional devices alsorequire complex monitoring and containment systems to ensure segregationfrom other bed vessel internals. In the example of catalytic reactors,this applies to segregating conventional redistribution devices fromcatalyst via “catalyst containment” equipment and measures. Any loss ofcatalyst containment can result in process and safety risks.Considerable measures are taken and bed vessel space dedicated toensuring that catalyst containment is ensured. The very presence of suchconventional redistribution and containment equipment and the difficultyof sustaining their stable and controlled operation can lead to problemsup to and including development of bed vessel shell hot spots leadingpotentially to rupture of the bed vessel itself.\

The very presence of such conventional structured engineered devicesconsumes space that could otherwise be consumed by more productive andmore profitable bed vessel internals, such as catalyst. An example ofsuch a structured engineered apparatus and its use as a flow distributoris shown in U.S. Pat. No. 7,314,551 granted Jan. 1, 2008 to UOP, LLC ofDes Plaines, Ill.

Improvements in this field of technology are desired.

SUMMARY

In accordance with the presently disclosed subject matter, variousillustrative embodiments of methods for facilitating the distributionand redistribution of the flow of one or more streams within vessels areprovided. Streams can include liquid and vapor streams, combinations ofthe two and mixtures of the two. Vessels can include those containingbeds of solid materials utilized for processing (hereinafter referred toas “bed vessels”).

In certain illustrative embodiments, a method of improving thedistribution and redistribution of the flow of one or more streams in abed vessel is provided. The bed vessel can be configured to have morethan one processing zone positioned vertically with respect to oneanother within the bed vessel with one uppermost processing zone and oneor more processing zones positioned downstream of the uppermostprocessing zone. The processing zones can contain beds of solidprocessing material elements. Redistribution treating zones can bedisposed downstream of an upstream processing zone and upstream of adownstream processing zone in order to facilitate effective andefficient redistribution of the flow of streams exiting the upstreamprocessing zone and entering said downstream processing zone. Oneprimary objective of such redistribution treating zones is to facilitatethe dispersal across the cross sectional area of the downstreamprocessing zone of the stream exiting the upstream processing zone andentering the downstream processing zone. The stream exiting theredistribution treating zone and entering the downstream processing zonecan be subdivided into small individual stream rivulets, which is animprovement over the channeled stream entering the redistributiontreating zone from the upstream processing zone. The dispersed streamrivulets affect improved contact with and utilization of the beds ofsolid processing material elements contained in the downstreamprocessing zone. The bed vessel's utilization and performance can besignificantly improved compared with the utilization and performance ofa bed vessel configuration that excludes the presence of saidredistribution treating zones.

In certain illustrative embodiments, a method of improving flowdistribution for one or more streams in, or at various locationsthroughout, a bed vessel is provided. The one or more streams can bepassed through an upstream processing zone and a downstream processingzone within the bed vessel. The upstream processing zone and downstreamprocessing zone can each contain one or more beds of solid processingmaterial elements. The one or more streams can also be passed through atleast one redistribution treating zone located between the upstreamprocessing zone and downstream processing zone. The redistributiontreating zone can contain treating material that redistributes the flowof the one or more streams. The beds of solid processing materialelements in the upstream processing zone can be separated from thetreating materials in the immediate downstream redistribution zone by apermeable barrier. Alternatively, the upstream processing zone materialscan be directly adjacent to and in contact with the treating materialsin the immediately downstream redistribution treating zone, without anyphysical equipment or barrier therebetween, such that the solidprocessing material elements from the upstream processing zone arecapable of at least partially commingling with the treating materials inthe immediately downstream redistribution treating zone to create acombo-zone containing both solid processing material elements andtreating materials and possessing both processing and streamdistribution treatment functionalities. Such migration is typicallylimited to the first few inches of depth of the redistribution treatingzone materials. The solid processing material elements can occupy atleast 20% of the volume of that portion of the layer of treatingmaterials contained in the redistribution treating zone into which thesolid processing material elements have migrated.

The redistribution treating zone can be downstream of and directlyadjacent to the upstream processing zone such that certain of the solidprocessing material elements from the upstream processing zone migrateinto the redistribution treating zone to create a combo-zone having bothsolid processing material elements and treating materials commingledtherein. In certain illustrative embodiments, there is no physicalequipment or barrier disposed in the vessel between the upstreamprocessing zone and the immediately downstream treating zone. The solidprocessing material elements in the upstream processing zone can migrateinto the layer of treating materials contained in the immediatelydownstream redistribution treating zone. Such migration is typicallylimited to the first few inches of the redistribution treating zonematerials. The solid processing material elements can occupy at least20% of the volume of that portion of the layer of treating materialscontained in the redistribution treating zone into which the solidprocessing material elements have migrated. In certain illustrativeembodiments, solid processing material elements are initially mixed withthe materials in the treating zone, such that co-mingling is achievedwithout the need for migration from other zones.

Redistribution treating zones can have a depth of one foot or less.Redistribution treating zones can have a depth of two feet or less.Redistribution treating zones can have a depth of four feet or less.

Redistribution treating zones can contain treating materials. Suchmaterials can be comprised of at least one layer of fixed, form-fitmaterial conforming to the interior dimensions of the bed vessel. Suchform-fit materials, such as fibrous meshes, provide porous structureswhich facilitate stream flow redistribution. Alternatively, treatingmaterials can be comprised of a plurality of treating elements. Thetreating elements can be individual treating elements. The treatingelements can be disposed in layers. The treating elements can berandomly-packed treating elements. One or more of the treating elementscan be ceramic reticulates. One or more of the treating elements canhave a quasi ellipsoid shape. One or more of the treating elements canhave a triaxial ellipsoid shape. One or more of the treating elementscan have an oblate spheroid shape. One or more of the treating elementscan have a prolate spheroid shape. One or more of the treating elementscan have a briquette shape. One or more of the treating elements canhave an asymmetrical spheroid shape. One or more of the treatingelements can have an aspherical ellipsoid shape. One or more of thetreating elements can have at least one opening formed therein. One ormore of the treating elements can have at least one opening formedtherethrough. One or more of the treating elements can have one or moreasperities formed on the surfaces thereof. The asperities can compriseone or more of flutes, fins, struts, filaments, spikes or hairs.

In certain illustrative embodiments, a method of improving the flowdistribution of one or more streams in and throughout a bed vessel isprovided in which redistribution treating zones containing a pluralityof treating elements is disposed immediately downstream of processingzones. In such a configuration, the solid processing material elementsin an upstream processing zone can migrate into the redistributiontreating zone and commingle with the treating elements in theredistribution treating zone to form a combo-zone with both solidprocessing material elements and treating elements and theirfunctionalities.

In certain illustrative embodiments, a method of improving the flowdistribution of one or more streams in and throughout a bed vessel isprovided in which redistribution treating zones containing a pluralityof treating elements is disposed immediately downstream of processingzones. In such a configuration, the solid processing material elementsin an upstream processing zone are commingled with the treating elementsin the redistribution treating zone to form a combo-zone with both solidprocessing material elements and treating elements and theirfunctionalities.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a partial cross-sectional side view of a bed vessel having aplurality of zones in accordance with an illustrative embodiment of thepresently disclosed subject matter.

FIG. 1B is a partial cross-sectional side view of a bed vessel having aplurality of zones with a close up view of adjacent zones in the bedvessel with a permeable barrier therebetween in accordance with anillustrative embodiment of the presently disclosed subject matter.

FIG. 2A is a partial cross-sectional side view of a bed vessel having aplurality of zones in accordance with an illustrative embodiment of thepresently disclosed subject matter.

FIG. 2B is a partial cross-sectional side view of a bed vessel having aplurality of zones with a close up view of a combo-zone between twoadjacent zones in the bed vessel in accordance with an illustrativeembodiment of the presently disclosed subject matter.

FIG. 3 is a graph showing flow redistribution test results for an emptytest vessel in accordance with an illustrative embodiment of thepresently disclosed subject matter.

FIG. 4 is a graph showing flow redistribution test results for a bed ofrandomly-packed ¾″ support ball test elements in accordance with anillustrative embodiment of the presently disclosed subject matter.

FIG. 5 is a graph showing flow redistribution test results for a bed ofrandomly-packed treating elements in accordance with an illustrativeembodiment of the presently disclosed subject matter.

While the presently disclosed subject matter will be described inconnection with the preferred embodiment, it will be understood that itis not intended to limit the presently disclosed subject matter to thatembodiment. On the contrary, it is intended to cover all alternatives,modifications, and equivalents, as may be included within the spirit andthe scope of the presently disclosed subject matter as defined by theappended claims.

DETAILED DESCRIPTION

In accordance with the presently disclosed subject matter, variousillustrative embodiments of methods for facilitating the redistributionand lateral redispersion of the flow of one or more streams within bedvessels are provided.

The concept of “redistribution” as described in the presently disclosedsubject matter concerns the division and dispersion of process streamsacross and throughout the internals contained within a bed vessel. Suchdivision and dispersion is facilitated by redistribution treating zonesdisposed to counter negative stream coalescing effects which causestream channeling and which, at best, prevent achievement of thedesigned performance of the processing zones installed within the bedvessel and, at worst, cause unsafe operating circumstances whichincrease operating risk.

In certain illustrative embodiments, disposed within such bed vesselsare internal materials and structures as well as multiple operatingzones. One type of operating zone can be a processing zone composed ofone or more beds of solid processing material. A second type ofoperating zone can be a treating zone. Treating zones can facilitate thedistribution and dispersion of the one or more streams exiting orentering processing zones. The distribution can facilitate contactbetween the streams and the beds of solid processing material elementscontained in the processing zones. A treating zone positioned between anupstream processing zone and a downstream processing zone can also becalled a redistribution treating zone.

In certain illustrative embodiments, redistribution treating zones canbe utilized in the bed vessels. The redistribution treating zones cancontain treating materials at sufficient depths and locations tofacilitate desired stream flow redistribution and redispersion acrossand throughout the downstream processing zone beds of solid processingmaterial elements.

In certain illustrative embodiments, the redistribution treatingmaterials can be comprised of at least one layer of fixed, form-fitmaterial conforming to the interior dimensions of the bed vessel.Alternatively, redistribution treating materials can be in the form of aplurality of individual treating elements that are randomly or otherwisepacked into treating zone layers.

In certain illustrative embodiments, the individual redistributiontreating elements can have a variety of shapes and sizes includingdiscs, spheres, rings, wagon wheels, hollow tubes and the like. The oneor more of the redistribution treating elements can have at least one ormore openings therein and/or therethrough. The one or more of theredistribution treating elements can have one or more asperities formedon the surfaces thereof which can include, without limitation, flutes,fins, struts, filaments, spikes or hairs. The one or more of theredistribution treating elements can be ceramic reticulates. Reticulatesare characterized as having one or more open cells which form aplurality of interconnected fluid flow pathways within and through theelements. Such pathways can have tortuous geometries. Suchredistribution treating elements with their openings, asperities andinterconnected internal fluid flow pathways have large surface areaswhich facilitate stream flow division and redistribution. Suchredistribution treating elements shall hereinafter be referred to as“treating elements.”

In certain illustrative embodiments, one or more of the treatingelements can have a quasi ellipsoid shape. For example, one or more ofthe quasi ellipsoid shaped treating elements can have a triaxialellipsoid shape. The one or more of the quasi ellipsoid shaped treatingelements can also have an oblate spheroid shape. The one or more of thequasi ellipsoid shaped treating elements can also have a prolatespheroid shape. The one or more of the quasi ellipsoid shaped treatingelements can also have a briquette shape. The one or more of the quasiellipsoid shaped treating elements can also have an asymmetricalspheroid shape. The one or more of the quasi ellipsoid shaped treatingelements can also have an aspherical ellipsoid shape.

In certain illustrative embodiments, the prolate, oblate, and asymmetricshaped quasi ellipsoids can have one mathematic model which can begeneralized to all three shapes. For example, the oblate and prolateshaped spheroids can be special cases of the generic, asymmetricellipsoid (a=b, b=c, or a=c), or shapes substantially similar to suchshapes, according to the following formula:

${\frac{x^{2}}{a^{2}} + \frac{y^{2}}{b^{2}} + \frac{z^{2}}{c^{2}}} = 1$

In certain illustrative embodiments, the briquette shape can be definedas the volumetric intersection of two or more elliptical cylinders wherethe major-axes of the elliptical faces of each cylinder are coplanar, orshapes substantially similar to such shapes.

In certain illustrative embodiments, redistribution treating zoneswithin bed vessels can have a depth of one foot or less. Alternatively,redistribution treating zones can have a depth of two feet or less.Alternatively, redistribution treating zones can have a depth of fourfeet or less.

In certain illustrative embodiments, a redistribution treating zonecontaining a plurality of randomly-packed individual treating elementscan be disposed immediately downstream of an upper processing zonewithout any barrier between the two zones. In such a configuration, theindividual solid processing material elements in the upper processingzone can migrate into the top few inches of the layer of treatingelements in the downstream redistribution treating zone and comminglewith these elements. Typical treating elements are each up to 50 timesthe size of individual solid processing material elements, in certainillustrative embodiments. With some solid processing material elements,treating elements can be over 100 times the size of individual solidprocessing material elements, in certain illustrative embodiments. Withsome solid processing material elements, treating elements can be over200 times the size of individual solid processing material elements, incertain illustrative embodiments.

The commingling of the individual solid processing material elementsfrom the upper processing zone with the treating elements of thedownstream redistribution treating zone results in solid processingmaterial elements consuming at least 20% of the volume of that portionof the redistribution treating zone into which said solid processingmaterial elements have migrated, in certain illustrative embodiments.Such a zone containing commingled solid processing material elements andtreating elements shall be referred to herein as a “combo-zone,” whereinsolid processing material elements are mixed with and/or have migratedinto a redistribution treating zone and are commingled with treatingelements present in the treating zone. Combo-zones are especiallybeneficial because they consume a modest amount of bed depth andsimultaneously and inexpensively improve both the processing andredistributive functions being performed within the bed vessel.

To facilitate commingling of combo-zone materials, loading proceduresfor bed vessel materials can call for sequential loading, for example,partial loading of a portion of the treating materials contained in aredistribution zone followed by partial loading of solid processingmaterial elements followed by additional partial loading of treatingelements followed by processing material elements. In certainillustrative embodiments, loading in this manner will facilitate themigration of materials from one zone to another within the vessel andcommingling of said materials in the combo-zone during processoperations. In certain illustrative embodiments, the material may alsobe mixed during loading such that commingling of materials in thecombo-zone is initially achieved without the need for any materials tomigrate from one zone to another within the vessel.

A redistribution treating zone can be of sufficient depth and locationto improve the utilization and performance of the immediately downstreamprocessing zones by efficiently facilitating the redistribution andredispersion of the flow of fluid streams exiting the redistributiontreating zone and entering the downstream processing zones.

Redistribution treating zones can obviate the need for costly and riskyconventional structured engineering devices and free valuable vesselvolume (that is, bed depth) for more productive uses such as additionalprocessing materials (e.g., catalyst).

In certain illustrative embodiments, bed vessel internals can beconfigured to include multiple processing zones, treating zones and/orcombo-zones. Overall bed vessel performance is dependent on the properperformance of each zone. Zones with processing functionality canperform their designed functions depending on the extent to whichstreams passing through said processing zones effectively interact withthe solid processing material elements in the processing zones. Zoneswith treating functionality can ensure that suitably distributed streamsare delivered to zones with processing functionality. Within thedimensional constraints of the bed vessels themselves, maximizing bedvessel performance can typically be achieved by minimizing the space(that is, bed depth) consumed by treating materials and maximizing thespace (that is, bed depth) consumed by processing material elements. Forexample, in certain illustrative embodiments, the presently disclosedsubject matter relates to processing zones of solid processing materialelements that are composed of relatively small individual elements whosesize varies from that of rice to that of corn kernels.

Relative to conventional solutions, the presently disclosed subjectmatter advantageously provides stream flow redistribution options that:(i) are less costly and less complex to design, fabricate, install,operate and maintain, (ii) free volume (that is, bed depth) in the bedvessel that can be better filled with more productive bed vesselinternals—such as additional solid processing material elements, (iii)avoid the operating risks associated with “containment” relatedfacilities and (iv) improve bed vessel performance and profitability viaincreased contact and interaction between streams and bed vesselprocessing materials.

Various illustrative embodiments of a method for redistributing the flowof one or more streams within a bed vessel are provided herein.Referring now to FIG. 1A, a bed vessel 10 is shown having two processingzones 40, 60 disposed therein. Bed vessel 10 is illustrated in adown-flow configuration, such that the one or more input streams 100will enter the bed vessel 10 at the inlet 20 and the one or more productstreams 600 will exit the bed vessel 10 at the outlet 70.

In certain illustrative embodiments, input streams 100 enter the vesseland pass through a “top bed” zone 30 containing elements 35. The top bedzone can facilitate distribution of the input streams 100 across thecross-section of processing zone 40. The top bed zone can alsofacilitate filtration of particulate contaminants contained in the inputstreams 100. The top bed zone can also mitigate undesired speciescontained in input streams 100. The stream 200 exiting the “top bed”zone 30 will possess these desirable characteristics before enteringprocessing zone 40.

In certain illustrative embodiments, process streams 200 are processedin process zone 40 and the resulting process streams 300 exit zone 40. Aredistribution treating zone 50 containing treating elements 55 can beprovided in the bed vessel 10 downstream of the first processing zone40. In certain illustrative embodiments, the flow of the one or morestreams 300 may be divided and redistributed in redistribution treatingzone 50 before being introduced to a downstream processing zone 60.

FIG. 1B shows an enlarged view of redistribution zone 50 containingtreating elements 55 disposed between processing zones 40 and 60. Inthis embodiment, a permeable barrier 80 is placed between processingzone 40 and redistribution zone 50 in order to separate the processingzone 40 from the redistribution treating zone 50 and prevent migrationof processing zone materials 45 while still allowing stream flow 300 topass through to zone 40 to zone 50. In other words, redistributiontreating zone 50 is directly adjacent to upstream processing zone 40 anda permeable barrier 80 is disposed between zone 50 and zone 40 such thatthe processing materials 45 from zone 40 cannot migrate into zone 50 butthe stream flow may pass through the barrier 80. In certain illustrativeembodiments, permeable barrier 80 can be a wire screen mesh.

FIGS. 2A and 2B show a bed vessel configuration similar to that in FIGS.1A and 1B. However, as shown in the enlarged view of FIG. 2B, no barrieris placed between the upper processing zone 40 and the redistributiontreating zone 50. In such an embodiment, a combo-zone can be formed (asdepicted in FIG. 2B) wherein individual elements of processing zonematerials 45 can migrate into and commingle with the top few inches ofthe layer of redistribution zone treating elements 55.

Such a combo-zone configuration lacking barrier constraints between theprocessing zone and the redistribution treating zone has the followingadvantages: (i) eliminates the need for and cost of design, fabrication,installation, operation and maintenance of such barriers, (ii) reducesthe space required to install such barriers, (iii) minimizes the spacerequired to achieve desired flow redistribution, (iv) allows for anincrease in processing zone performance due to the addition ofprocessing zone materials in the space freed by the absence of barriers,(v) adds additional processing zone performance due to the presence ofprocessing zone materials in the combo-zone and (vi) increases theperformance and profitability of the bed vessel by increasinginteraction between streams and the vessel's processing zone materials.

In certain illustrative embodiments, the combo-zone will comprise thefirst few inches of depth of the redistribution treating zone 50. Thisis in the context of a bed vessel that may be as tall as 100 feet ormore with operating zones that substantially fill the vessel. In certainillustrative embodiments, the combo-zone will comprise about the firsttwo (2) inches of depth of the redistribution treating zone 50. Incertain illustrative embodiments, the combo-zone will comprise about thefirst six (6) inches of depth of the redistribution treating zone 50. Incertain illustrative embodiments, the combo-zone will comprise the firsttwelve (12) inches of depth of the redistribution treating zone 50.

As shown in FIG. 1A, redistribution treating zone 50 can be located ator near an upper region of vessel 10, in certain illustrativeembodiments, to facilitate redistribution of process steam flow fromprocessing zone 40 into processing zone 60 and/or other lower-positionedzones within vessel 10. In this regard, there can be one or moreprocessing zones and redistribution zones disposed between streams 500and 600 in vessel 10 that are located downstream from the zones asdepicted in FIG. 1A.

In certain illustrative embodiments, stream flow redistribution isprimarily facilitated by contacting the stream with the surfaces of theredistribution zone treating elements. These surfaces include theexternal surfaces of the treating elements and the internal surfaces ofthe treating elements. The internal geometries of treating elementscreate large surface areas formed by openings, asperities and aplurality of interconnected internal fluid flow pathways.

In certain illustrative embodiments, the surface area of individualtreating elements can be from 70% to 90% internal surface area with theremainder being external surface area. A result is that, for a givenvolume of treating elements, treating element shapes that pack moredensely provide more surface area than treating element shapes that packless densely. Stream flow redistribution capability per volume of packedtreating elements, therefore, increases as packing density increases.This applies as well to the external void space between packed treatingelements which decreases as packing density increases.

In certain illustrative embodiments, the amount of material required ina treating zone to achieve a desired level of stream flow redistributionin a bed vessel is primarily a function of the total volume of materialsnot including voidage external to the treating elements. Relative tocylindrical reticulates, quasi-ellipsoid shaped treating elements tendto pack with less void space between individual elements. For example,treating zones of quasi-ellipsoidal shaped treating elements can haveexternal void space of 25 to 35% compared to 40 to 55% for treatingzones of cylindrical reticulates. To achieve a desired level of streamflow redistribution, this can result in treating zones ofquasi-ellipsoid shaped treating elements less deep than those formed byan equivalent amount of cylindrical reticulates. This saves space in thebed vessel.

Further, the ability of a treating zone of individual treating elementsto redistribute the flow of one or more process streams depends in parton the number of contact points each treating element has with itsneighboring elements. Maximizing contact points facilitates stream flowredistribution thru the treating zone. Treating zones ofquasi-ellipsoidal treating elements can have 60 to 90% more of suchcontact points than do equivalent layers of cylindrical or sphericalreticulates.

To facilitate a better understanding of the presently disclosed subjectmatter, the following examples of certain aspects of certain embodimentsare given. In no way should the following examples be read to limit, ordefine, the scope of the presently disclosed subject matter.

Experiments were performed to demonstrate process stream redistribution,including the mitigation/elimination/disruption/reduction of channeling,of a process stream exiting an upstream bed vessel processing zone andtransiting/passing thru a bed vessel redistribution treating zone inaccordance with certain illustrative embodiments of the presentlydisclosed subject matter.

A fabricated testing structure was assembled including a verticalcylindrical vessel approximately 12 inches in diameter and over 36inches tall. A nozzle located above the centerpoint of the vessel wasused to pass liquid into the vessel. The cylindrical vessel providedsufficient space for a bed of randomly-packed test elements up to 36inches deep. Over 300 holes, each ¼″ in diameter were drilled in aregular grid pattern thru the bottom of the vessel. Each hole wasindividually connected to a plastic tube utilized to collect and measureliquid exiting the vessel thru the hole. These holes represent a twodimensional grid zone of the cross-sectional area of the vessel. Theliquid collected thru each hole shows the distribution of the inletliquid across the cross-sectional area of the vessel.

Liquid was pumped thru the nozzle into the vessel. The stream of liquidemulates channeled streams which occur in the processing zones ofcommercial bed vessels. In one test run, the vessel was empty. In othertest runs, various types and depths of test elements were installed. Ineach test run sufficient time was elapsed to obtain representativequantities of liquid via the tube-connected holes in the bottom of thevessel. Data collection and analysis produced graphical plotsdemonstrating the ability of the test elements to laterally disperse theliquid thru the test element bed and exit the vessel thru the holes inthe bottom of the vessel.

In a typical run in which test elements are placed in the vessel, theliquid is allowed to disperse as it flows around and thru the testelements, exits the vessel thru the grid zone holes and is collected inthe tubes below. The amount of water collected in each tube is measuredand graphs are prepared which show the extent to which the elementsfacilitate flow redistribution.

The graphical plots of flow redistribution test results are shown inFIGS. 4-6. Shown are the amounts of liquid recovered thru the tubesconnected to the holes in the vessel grid zone. FIG. 4 shows the flowredistribution test results for an empty test vessel. FIG. 5 shows theflow redistribution test results for a bed of randomly-packed ¾″ supportball test elements. FIG. 6 shows the results for a bed ofrandomly-packed treating elements according to the presently disclosedsubject matter.

In FIG. 4, when there were no test elements in the vessel and liquid wasrun into an empty cylinder, the bank of tubes show just over 5% of theliquid being laterally distributed as measured by the result L_(fact).The greater than 5% result includes the liquid which passed thru thecenter line holes of the vessel demonstrating that virtually all theliquid exited the vessel through the holes at or near the center of thevessel grid zone. In FIG. 5, the bed of randomly-packed support ballsachieved just over 55% lateral distribution of the liquid across thevessel grid zone. In FIG. 6, the test run using a bed of randomly-packedtreating elements according to the presently disclosed subject matterachieved over 92% lateral distribution of the liquid across the vesselgrid zone.

It can be seen from these test results that beds of the treatingelements according to the presently disclosed subject matter canfacilitate redistribution of channeled liquid streams exiting anupstream processing zone. Said redistributed streams can then enter adownstream processing zone as a laterally dispersed stream whichprovides improved contact between the stream and the processing zoneelements in the downstream processing zone.

It is to be understood that the presently disclosed subject matter isnot to be limited to the exact details of construction, operation, exactmaterials, or embodiments shown and described, as obvious modificationsand equivalents will be apparent to one skilled in the art. Accordingly,the presently disclosed subject matter is therefore to be limited onlyby the scope of the appended claims.

What is claimed is:
 1. A method of improving flow distribution of one ormore streams in a process vessel comprising: passing the one or morestreams through an upstream processing zone and a downstream processingzone within the process vessel, the upstream processing zone anddownstream processing zone each containing one or more beds ofprocessing materials, wherein the processing materials comprisecatalyst; and passing the one or more streams through a redistributiontreating zone located between, and adjacent to both of, the upstreamprocessing zone and downstream processing zone, wherein the entire depthof the redistribution zone comprises a plurality of individual, packedtreating elements, and wherein the treating elements comprise a materialother than the catalyst of the processing materials, wherein theredistribution treating zone has a depth of four feet or less, andwherein the treating elements have a hollow tube shape, and wherein thetreating elements are up to 100 times the size of the individualprocessing materials within the process vessel.
 2. The method of claim1, wherein no space between the upstream processing zone and theredistribution treating zone is consumed by a structure internal to theprocess vessel.
 3. The method of claim 1, wherein the redistributiontreating zone is directly adjacent to the upstream processing zone, andwherein the processing materials in the upstream processing zone aresized such that at least some of the processing materials can migrateinto the redistribution treating zone to create a combo-zone having bothprocessing zone functionality and treating zone functionality.
 4. Amethod of improving flow distribution of one or more streams in aprocess vessel comprising: passing the one or more streams through anupstream processing zone and a downstream processing zone within theprocess vessel, the upstream processing zone and downstream processingzone each containing one or more beds of processing materials; andpassing the one or more streams through a redistribution treating zonelocated between, and adjacent to both of, the upstream processing zoneand downstream processing zone, wherein the entire depth of theredistribution zone comprises a plurality of individual, packed treatingelements, and wherein the processing materials and the treating elementscomprise different materials, and wherein the redistribution treatingzone has a depth of four feet or less, and wherein the treating elementshave a hollow tube shape, and wherein the treating elements are up to100 times the size of the individual processing materials within theprocess vessel.
 5. The method of claim 4, wherein the processingmaterials comprise catalyst and the treating elements comprise amaterial other than the catalyst of the processing material.
 6. A methodof improving flow distribution of one or more streams in a processvessel comprising: passing the one or more streams through an upstreamprocessing zone and a downstream processing zone within the processvessel, the upstream processing zone and downstream processing zone eachcontaining one or more beds of processing materials; and passing the oneor more streams through a redistribution treating zone located between,and adjacent to both of, the upstream processing zone and downstreamprocessing zone, wherein the treating elements in the redistributionzone are larger in size than the processing materials in the upstreamprocessing zone and downstream processing zone, and wherein the depth ofthe redistribution zone is less than the depth of the downstreamprocessing zone, and wherein the redistribution treating zone has adepth of four feet or less, and wherein the treating elements have ahollow tube shape, and wherein the treating elements are up to 100 timesthe size of the individual processing materials within the processvessel.
 7. The method of claim 6, wherein the depth of theredistribution zone is also less than the depth of the upstreamprocessing zone.
 8. A method of improving flow distribution of one ormore streams in a process vessel comprising: passing the one or morestreams through an upstream processing zone and a downstream processingzone within the process vessel, the upstream processing zone anddownstream processing zone each containing one or more beds ofprocessing materials; and passing the one or more streams through aredistribution treating zone located between, and adjacent to both of,the upstream processing zone and downstream processing zone, wherein theentire depth of the redistribution zone comprises a plurality ofindividual, packed treating elements, and wherein the redistributiontreating zone has a depth of four feet or less, and wherein the treatingelements have a hollow tube shape, and wherein the treating elements arerandomly packed in the redistribution zone and wherein a liquid streampassing through the redistribution zone is capable of passing around andthrough the treating elements, and wherein the treating elements are upto 100 times the size of the individual processing materials within theprocess vessel.
 9. The method of claim 7, wherein a plurality ofchanneled liquid streams exit the upstream processing zone, and whereinthe treating elements facilitate redistribution of the channeled liquidstreams, and wherein the redistributed streams enter the downstreamprocessing zone as laterally dispersed streams such that there isimproved contact between the laterally dispersed streams and theprocessing elements in the downstream processing zone.